HLA-C and Cachexia: Although no differences in SM-MHC protein levels were observed, both α-SMA (no-cachexia (NC): −1.7-fold, p < 0.001; cachexia (C): −1.6-fold, p < 0.001) and SM22-α (NC: −2.3-fold, p < 0.001; C: −3.2-fold, p < 0.001) protein levels were markedly decreased by the tumor organoid secretome of both cachectic and non-cachectic patients compared to the control condition (Figure 2a,b).